Chapter 08.pdf

chapter

Conditioning and Learning

THEME:

The principles of learning can

be used to understand and

manage behavior.

Key Questions

What is learning?

What does punishment do to behavior?

How does classical conditioning occur?

What is cognitive learning?

Does conditioning affect emotions?

Does learning occur by imitation?

How does operant conditioning occur?

How does conditioning apply to practical

problems?

Are there different kinds of operant

reinforcement?

How are we inﬂ uenced by patterns of

reward?

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Preview

What Did You Learn in School Today?

deposit your last two quarters to buy a candy bar. Then you

press the button, and . . . nothing happens. Being civilized

and in complete control, you press the other buttons, try

the coin return, and look for an attendant. Still nothing.

Your stomach growls. Impulsively, you give the machine a

little kick (just to let it know how you feel). Then, as you

turn away, out pops a candy bar plus 25 cents change.

Once this happens, chances are good that you will repeat

the “kicking response” in the future. If it pays off several

times more, kicking vending machines may become a

regular feature of your behavior. In this case, learning is

based on operant conditioning (also called instrumental

learning).

Classical and operant conditioning reach into every

corner of our lives. Are you ready to learn more about

learning? If so, read on!

When one of your authors was in college, he discovered an

intriguing ﬂ aw in the dorm plumbing: Flush a toilet while

someone was taking a shower and the cold water pressure

would suddenly drop. This caused the shower to become

scalding hot. Naturally, the shower victim screamed in

terror as his reﬂ exes caused him to leap backward in pain.

Soon he discovered that if all the toilets were ﬂ ushed at

once, the effects were multiplied many times over!

A toilet has to be one of the world’s most uninspiring

stimuli. But for a time, a whole ﬂ ock of college students

twitched involuntarily whenever they heard a toilet ﬂ ush.

Their reactions were the result of classical conditioning, a

basic type of learning. Classical conditioning is one of the

topics of this chapter.

Now, let’s say that you are at school and you feel like you

are “starving to death.” You locate a vending machine and

What Is Learning—Does

Practice Make Perfect?

teach a child to be neat by praising him for picking up his toys.

Learning can also occur in other ways. For instance, if a girl gets

stung by a bee, she may learn to associate pain with bees and to

fear them. In this case, the girl’s fear is reinforced by the discom-

fort she feels immediately after seeing the bee. Later, you’ll dis-

cover how such varied experiences lead to learning.

Most behavior is learned. Imagine if you suddenly lost all you had

ever learned. What could you do? You would be unable to read,

write, or speak. You couldn’t feed yourself, ﬁ nd your way home,

drive a car, play the bassoon, or “party.” Needless to say, you

would be totally incapacitated. (Dull, too!) Learning is a relatively

permanent change in behavior due to experience. Notice that this

deﬁ nition excludes temporary changes caused by motivation, fa-

tigue, maturation, disease, injury, or drugs. Each of these can alter

behavior, but none qualiﬁ es as learning.

Isn’t learning the result of practice? It depends on what you mean

by practice. Merely repeating a response will not necessarily pro-

duce learning. You could close your eyes and swing a tennis racket

hundreds of times without learning anything about tennis. Rein-

forcement is the key to learning. Reinforcement refers to any

event that increases the probability that a response will occur

again. A response is any identiﬁ able behavior. Responses may be

observable actions, such as blinking, eating a piece of candy, or

turning a doorknob. They can also be internal, such as having a

faster heartbeat.

To teach a dog a trick, we could reinforce correct responses by

giving the dog some food each time it sits up. Similarly, you could

Antecedents and Consequences

Unlocking the secrets of learning begins with noting what happens

before and after a response. Events that precede a response are

called antecedents. For example, Ashleigh, age 3, has learned that

when she hears a truck pull into the driveway, it means that Daddy

is home. Ashleigh runs to the front door, where she gets a hug from

her father. Effects that follow a response are consequences. The

hug is what reinforces Ashleigh’s tendency to run to the door. As

this suggests, paying careful attention to the “before and after” of

learning is a key to understanding it.

Classical Conditioning

Classical conditioning is based on what happens before we re-

spond. It begins with a stimulus that reliably triggers a response.

Imagine, for example, that a puff of air (the stimulus) is aimed at

your eye. The air puff will make you blink (a response) every time.

The eyeblink is a reﬂ ex (automatic, nonlearned response).

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Conditioning and Learning

263

Classical Conditioning—Does

the Name Pavlov Ring a Bell?

Now, assume that we sound a horn (another stimulus) just be-

fore each puff of air hits your eye. If the horn and the air puff oc-

cur together many times, what happens? Soon, the horn alone

will make you blink. Clearly, you’ve learned something. Before,

the horn didn’t make you blink. Now it does. Similarly, if your

mouth waters each time you eat a cookie, you may learn to sali-

vate when you merely see a cookie, a picture of cookies, a cookie

jar, or other stimuli that preceded salivation.

In classical conditioning, an antecedent stimulus that doesn’t

produce a response is linked with one that does (a horn is associ-

ated with a puff of air to the eye, for example). We can say that

learning has occurred when the new stimulus will also elicit (bring

forth) responses ( ● Figure 8.1).

How was classical conditioning discovered? At the beginning of the

twentieth century, something happened in the lab of Russian

physiologist Ivan Pavlov that brought him lasting fame: Pavlov’s

subjects drooled at him.

Actually, Pavlov was studying digestion. To observe salivation,

he placed meat powder or some tidbit on a dog’s tongue. After do-

ing this many times, Pavlov noticed that his dogs were salivating

before the food reached their mouths. Later, the dogs even began

to salivate when they saw Pavlov enter the room. Was this mis-

placed affection? Pavlov knew better. Salivation is normally a re-

ﬂ ex. For the animals to salivate at the mere sight of food, some

type of learning must have occurred. Pavlov called it conditioning

( ● Figure 8.2). Because of its importance in psychology’s history,

it is now called classical conditioning (also known as Pavlovian con-

ditioning or respondent conditioning ).

Operant Conditioning

In operant conditioning, learning is based on the consequences

of responding. A response may be followed by a reinforcer (such

as food). Or by punishment. Or by nothing. These results deter-

mine whether a response is likely to be made again (see ● Figure

8.1). For example, if you wear a particular hat and get lots of com-

pliments (reinforcement), you are likely to wear it more often. If

people snicker, insult you, call the police, or scream (punish-

ment), you will probably wear it less often.

Now that you have an idea of what happens in the two basic

kinds of learning, let’s look at classical conditioning in more

detail.

Classical Conditioning

Result: Horn

Eyeblink

Key

relationship

● Figure 8.2 An apparatus for Pavlovian conditioning. A tube carries

saliva from the dog’s mouth to a lever that activates a recording device (far

left). During conditioning, various stimuli can be paired with a dish of food

placed in front of the dog. The device pictured here is more elaborate than

the one Pavlov used in his early experiments.

Stimulus

Horn

Stimulus

Air puff

Response

Eye blink

Operant Conditioning

Result: Whistle

Sit-up

Key

relationship

Stimulus

Whistle

Response

Sit-up

Reinforcer

Food

Learning Any relatively permanent change in behavior that

can be attributed to experience.

Reinforcement Any event that increases the probability that a

particular response will occur.

Antecedents Events that precede a response.

Consequences Effects that follow a response.

Reﬂ ex An innate, automatic response to a stimulus; for

example, an eyeblink.

Classical conditioning A form of learning in which reﬂ ex

responses are associated with new stimuli.

Operant conditioning Learning based on the consequences of

responding.

Antecedents

Response

Consequences

Time

● Figure 8.1 In classical conditioning, a stimulus that does not produce

a response is paired with a stimulus that does elicit a response. After many

such pairings, the stimulus that previously had no effect begins to produce

a response. In the example shown, a horn precedes a puff of air to the eye.

Eventually the horn alone will produce an eyeblink. In operant conditioning,

a response that is followed by a reinforcing consequence becomes more

likely to occur on future occasions. In the example shown, a dog learns to sit

up when it hears a whistle.

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264

CHAPTER 8

Pavlov’s Experiment

How did Pavlov study conditioning? After Pavlov observed that food

made his dogs salivate, he began his classic experiments (see

● Figure 8.2). To begin, he rang a bell. At ﬁ rst, the bell was a neu-

tral stimulus (the dogs did not respond to it by salivating). Imme-

diately after Pavlov rang the bell, he placed meat powder on the

dog’s tongue, which caused reﬂ ex salivation. This sequence was

repeated many times: bell, meat powder, salivation; bell, meat

powder, salivation. Eventually (as conditioning took place), the

dogs began to salivate when they heard the bell ( ● Figure 8.3). By

association, the bell, which before had no effect, began to evoke

the same response that food did. This was shown by sometimes

ringing the bell alone. Then the dog salivated, even though no

food had been placed in its mouth.

Psychologists use several terms to describe these events. The

bell starts out as a neutral stimulus (NS). In time, the bell be-

comes a conditioned stimulus (CS) (a stimulus that, because of

learning, will elicit a response). The meat powder is an uncondi-

tioned stimulus (US) (a stimulus innately capable of producing a

response). Notice that the dog did not have to learn to respond to

the US. Such stimuli naturally trigger reﬂ exes or emotional reac-

tions.

Because a reﬂ ex is innate, or “built in,” it is called an uncondi-

tioned (nonlearned) response (UR). Reﬂ ex salivation was the UR

in Pavlov’s experiment. When Pavlov’s bell also produced saliva-

tion, the dog was making a new response. Thus, salivation had

become a conditioned (learned) response (CR) (see ● Figure 8.3).

■ Table 8.1 summarizes the important elements of classical condi-

tioning.

Are all these terms really necessary? Yes, because they help us rec-

ognize similarities in various instances of learning. Let’s summa-

rize the terms using an earlier example:

Before Conditioning

Example

US → UR

Puff of air → eye blink

NS → no effect

Horn → no effect

After Conditioning

Example

CS → CR

Horn → eye blink

Now let’s see if we can explain the shower and ﬂ ushing toilet

example described earlier. The unconditioned, or nonlearned, re-

sponse was a reﬂ ex jump from the hot water. The unconditioned

stimulus was the hot water. The conditioned stimulus was the

sound of a ﬂ ushing toilet. That is, the ﬂ ushing sound was at ﬁ rst

neutral and had no effect. But as a result of conditioning, it be-

came capable of triggering a reﬂ ex. See “Coping with Chemo” for

an example of how classical conditioning is being used to solve a

clinical problem.

TABLE 8.1

Elements of Classical Conditioning

ELEMENT

SYMBOL

DESCRIPTION

EXAMPLE

Neutral stimulus

A stimulus that does not evoke a response

Bell

Unconditioned stimulus

A stimulus innately capable of eliciting a response

Meat powder

Conditioned stimulus

A stimulus that evokes a response because it has been repeatedly paired with an

Bell

unconditioned stimulus

Unconditioned response

An innate reﬂ ex response elicited by an unconditioned stimulus

Reﬂ ex salivation

Conditioned response

A learned response elicited by a conditioned stimulus

Salivation

Before Conditioning

During Conditioning (Acquisition)

Test for Conditioning

Time

Bell

(CS)

Bell

(CS)

Salivation

(CR)

Bell

(NS)

No salivation

Conditioned

reflex

Associated

Meat powder

(US)

Salivation

(UR)

Meat powder

(US)

Salivation

(UR)

Reflex

● Figure 8.3 The classical conditioning procedure.

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Conditioning and Learning

265

THE CLINICAL FILE

Coping with Chemo

Our hearts go out to children with cancer. Even the treatment,

chemotherapy, makes them miserable because it causes nausea

and vomiting. In a cruel twist, nausea can occur before a chemo-

therapy session begins. Typically, it is triggered by certain sights or

tastes, like the sight of the treatment center or the taste of a food

the child ate before an earlier chemotherapy session.

In classical conditioning terms, chemotherapy is a US that leads

to nausea, which is a UR. The sight of the treatment center or the

taste of food eaten before treatment is a neutral stimulus that is

associated with nausea and vomiting, making it a CS. These sights

or tastes can now elicit anticipatory nausea (a CR) even at times

when the child doesn’t receive chemotherapy (Chance, 2006).

In nature, many species are biologically prepared to associate

speciﬁ c locations and tastes with nausea. For example, animals

that eat contaminated food get sick and vomit. Later, the same

locations or tastes trigger anticipatory nausea and vomiting. These

reactions discourage animals from eating potentially dangerous

food.

Unfortunately, conditioned nausea can also affect young can-

cer patients. Imagine that Gita’s parents lovingly give her pizza,

her favorite meal, before she has her ﬁ rst chemotherapy session.

The chemotherapy makes her nauseous and she vomits. From that

time on, the taste of pizza makes her feel sick.

Is there any way to prevent conditioned nausea? No, but classical

conditioning can provide some relief (Taylor, 2002). For instance,

meals eaten before chemotherapy can be ﬂ avored with an unusual

taste, such as peppermint. The unique ﬂ avor “attracts” the condi-

tioning, so that other tastes don’t become linked with nausea. In

this way, Gita can continue to enjoy her favorite meal, pizza, during

the course of her treatments (Bovbjerg et al., 1992).

Principles of Classical Conditioning—

Teach Your Little Brother to Salivate

To observe conditioning, you could ring a bell and squirt lemon

juice into a child’s mouth. By repeating this procedure several

times, you could condition the child to salivate to the bell. The

child might then be used to explore other aspects of classical con-

ditioning. Let’s see how conditioning occurs.

Acquisition

During acquisition, or training, a conditioned response must be

reinforced (strengthened) (

Test trials during acquisition

Test trials during extinction

● Figure 8.4 Acquisition and extinction of a conditioned response. (After

Pavlov, 1927.)

Figure 8.4). Classical conditioning is

reinforced when the CS is followed by, or paired with, an uncondi-

tioned stimulus. For our child, the bell is the CS, salivating is the

UR, and the sour lemon juice is a US. To reinforce salivating to the

bell, we must link the bell with the lemon juice. Conditioning

will be most rapid if the US (lemon juice) follows immediately after

the CS (the bell). With most reﬂ exes, the optimal delay between

CS and US is from one-half second to about 5 seconds (Chance,

2006).

●

Neutral stimulus A stimulus that does not evoke a response.

Conditioned stimulus A stimulus that evokes a response

because it has been repeatedly paired with an unconditioned

stimulus.

Unconditioned stimulus A stimulus innately capable of

eliciting a response.

Unconditioned response An innate reﬂ ex response elicited by

an unconditioned stimulus.

Conditioned response A learned response elicited by a

conditioned stimulus.

Acquisition The period in conditioning during which a

response is reinforced.

Higher order conditioning Classical conditioning in which a

conditioned stimulus is used to reinforce further learning; that

is, a CS is used as if it were a US.

Higher Order Conditioning

Once a response is learned, it can bring about higher order

conditioning. In this case, a well-learned CS is used to reinforce

further learning. That is, the CS has become strong enough to be

used like an unconditioned stimulus. Let’s illustrate again with

our salivating child.

As a result of earlier learning, the bell now makes the boy sali-

vate. (No lemon juice is needed.) To go a step further, you could

clap your hands and then ring the bell. (Again, no lemon juice

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